JPH1078607A - Method and structure for mounting conversion lens - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately mount a high-magnification convesion lens whose aberration is accurately compensated on an equipment side lens. SOLUTION: This structure is provided with the lens frame 2 of an optical equipment holding the equipment side lens 1 and a holding frame 5 holding the conversion lens 4 and attachably/detachably connected to the end of the lens frame 2; and the holding frame 5 is formed to project to the end of the lens frame 2 side, and has a 1st abutting part 8 abutting on the outer peripheral part of the lens surface 1a of the equipment side lens 1 when the holding frame 5 is attached to the lens frame 2 and a 2nd abutting part 10 formed to be opposed to the 1st abutting part 8 and fixing the lens 4 by making the outer peripheral part of the lens surface 4a of the lens 4 abut on. The lens 4 is accurately mounted by the 1st and the 2nd abutting parts 8 and 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and structure for mounting a conversion lens mounted on an optical device in order to change the magnification of a device-side lens of the optical device.

[0002]

2. Description of the Related Art A front conversion lens and a rear conversion lens which change magnification by being attached to a front end or a rear end of an apparatus-side lens without replacing the apparatus-side lens of an optical apparatus are a wide-angle camera, a telephoto conversion lens, It is widely used in close-up lenses, auxiliary objective lenses for stereomicroscopes, and the like. As described above, a method of changing the magnification by adding a conversion lens while using the device-side lens originally provided in the optical device is economical, and the magnification can be easily changed.

[0003] In a compact camera, such a conversion lens is mounted by putting it on the camera body.
As described in Japanese Patent No. 422,422 and US Pat. No. 3,459,991, while forming a screw on the front end of a lens frame on the device side, forming a screw on a holding frame for holding a conversion lens, and screwing these screws together. , Its being made.

FIG. 5 shows such a conventional mounting method.
The lens frame 2 is attached to the main body 7 of the optical device, and the device-side lens 1 such as an objective lens is held inside the lens frame 2. The distal end portion of the lens frame 2 extends forward from the device-side lens 1, and a female screw 3 is formed inside the extended portion.

[0005] Reference numeral 5 denotes a holding frame for holding the conversion lens. The rear end of the holding frame is extended toward the lens frame 2, and a male screw 6 is formed in the extended portion. The holding frame 5 has its male screw 6 screwed into the female screw 3 of the lens frame 2, and the rear end surface of the holding frame 5 is brought into contact with the front end surface of the lens frame 2 to be joined to the lens frame 2, whereby the conversion lens 4 is performed.

In such a conventional mounting mechanism, the distance between the device-side lens 1 and the conversion lens 4 is determined by the distance between the contact portion where the device-side lens 1 contacts the lens frame 2 and the tip of the lens frame 2. a and the conversion lens 4 is a holding frame 5
Is determined by the sum of the contact portion that abuts the lens frame 2 and the distance b at which the tip of the holding frame 5 abuts the lens frame 2, and further adds the errors of these.

Further, the lens 1 of the optical apparatus is often installed from the front end of the lens frame 2 so that an error to the optical apparatus body is minimized. As a result, the apparatus-side lens 1 and the conversion lens 4 The error of the thickness of the device-side lens 1 is added to the interval. In addition, in the case of a complicated lens having a large number of lenses, an error is further added. If the lens interval is not adjusted to the value of the lens design, a lens having higher aberration correction and higher power (magnification) causes a larger error in performance and magnification.

[0008]

As described above, although a conversion lens is a very effective method for changing the magnification of an optical device, it is only a certain degree of accuracy because of the conventional mounting structure using screws. Can not be fixed.
For this reason, in the case of a high-performance lens that suppresses aberrations and the like that require the precision of the lens spacing and the mutual positional relationship of the lenses as required in the lens design, particularly a lens that converts to high magnification, even if the optical design of the conversion lens is possible, It was difficult to secure the performance by actually mounting.

In this case, in some cases, it is possible to secure the performance by setting the dimensional tolerance tightly. However, setting the strict tolerance of the lens frame of the optical device does not mean that the conversion is not performed on all the optical devices. The result is a trade-off with the economics that are advantages of lenses. For this reason, conventionally, the conversion lens is generally recognized as a low-cost simple method when the dedicated optical system is expensive, with the recognition that the performance is slightly inferior.

The present invention utilizes a high performance of a conversion lens which converts a magnification while utilizing the high performance of a lens on the device side of an optical apparatus, and a high performance and high magnification with excellent correction of aberration while utilizing the convenience of a conversion lens. An object of the present invention is to provide a conversion lens mounting method and a mounting structure to which a conversion lens can be mounted.

[0011]

According to the method of mounting a conversion lens of the present invention, an end of a holding frame for holding a conversion lens is held in contact with an outer peripheral portion of a lens surface of a device side lens of an optical apparatus. It is characterized in that the conversion lens is positioned with respect to the device-side lens via the frame.

By fixing the end of the holding frame to the lens surface of the device-side lens, the fixing position of the holding frame with respect to the device-side lens is determined. Since the conversion lens is fixed to this holding frame, the distance between the device side lens and the conversion lens is determined by the contact of the holding frame,
Positioning is performed on the conversion lens.

[0013] The conversion lens mounting structure of the present invention includes a lens frame of an optical device holding a device-side lens, and a holding frame holding the conversion lens and detachably coupled to an end of the lens frame. The holding frame is formed so as to protrude from an end on the lens frame side, and when the holding frame is mounted on the lens frame, a first contact portion that contacts an outer peripheral portion of a lens surface of the device-side lens; A second contact portion formed to face the first contact portion and fixing the conversion lens by contacting an outer peripheral portion of a lens surface of the conversion lens. I do.

The distance between the device-side lens and the conversion lens is determined by the first contact portion abutting on the lens surface of the device-side lens. On the other hand, since the conversion lens is in contact with and fixed to the second contact portion formed to face the first contact portion, the conversion lens can be positioned with respect to the device-side lens.

In the conversion lens mounting structure of the present invention, the holding frame and the lens frame may be connected by screwing or may be connected by fitting.

Further, in these cases, the holding frame includes an inner frame in which the first contact portion and the second contact portion are formed, an inner frame for accommodating the inner frame, and an end of the lens frame. An outer frame detachably connected to the unit and an urging member for urging the inner frame to move in the direction of the lens frame.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION

(Embodiment 1) FIG. 1 shows Embodiment 1 of the present invention. A lens frame 2 for holding a device-side lens 1 such as an objective lens is attached to a main body 7 of an optical device. The lens frame 2 has an extension 2a extending forward from the device-side lens 1, and a female screw 3 is formed on the inner surface of the extension 2a.

On the other hand, the conversion lens 4 is held by a holding frame 5. A small-diameter extending portion 5a is formed at an end of the holding frame 5 on the lens frame 2 side, and a male screw 6 that is screwed to a female screw of the lens frame 2 is formed on an outer surface of the extending portion 5a. I have.

A first contact portion 8 is provided on the extension 5a of the holding frame 5.
Are integrally formed. The first contact portion 8 has a cylindrical shape, and is inclined so that the diameter thereof is gradually smaller than that of the extension portion 5a. The end contacts the outer peripheral portion of the lens surface 1a of the device-side lens 1.

Further, a cylindrical second contact portion 10 for fixing the conversion lens 4 by holding the outer peripheral portion of the lens surface 4a of the conversion lens 4 facing the device-side lens 1 in the holding frame 5 is provided. Is formed. The second contact portion 10 and the first contact portion 8 are formed to face each other so that their parallelism and concentricity are equal.

In this embodiment, the male screw 6 of the holding frame 5
Is screwed into the female screw 3 of the lens frame 2 to mount the conversion lens 4. By this screwing, the first contact portion 8 of the holding frame 5 contacts the outer peripheral portion of the lens surface 1a of the device-side lens 1.

In this structure, the distance between the device-side lens 1 and the conversion lens 4 is determined by the first contact portion 8 of the holding frame 5 contacting the device-side lens 1 and the conversion lens 4.
Is determined by the distance a with respect to the second contact portion 10 with which the first contact portion 8 contacts, and the first contact portion 8 and the second contact portion 10 are formed so as to face each other. , 4 are precisely fixed. In this case, the thickness of the lenses 1 and 4 and the accuracy of the contact portion where the lens frame 2 and the holding frame 5 contact do not affect the positional relationship between the lenses 1 and 4 at all.

Further, in this embodiment, when the first contact portion 8 comes into contact with the lens surface 1a of the device-side lens 1, the holding frame 5 is automatically moved to the spherical lens surface 1a of the device-side lens 1. Fixed along the center of the In addition, the conversion lens 4 is held by the cylindrical second contact portion 10 of the holding frame 5 so that the parallelism and concentricity of the first and second contact portions 8 and 10 are equal. Since it is set, the concentricity of the lenses 1 and 4 can also be secured.

(Embodiment 2) FIG. 2 shows Embodiment 2 and the same parts as those in FIG. 1 are assigned the same reference numerals. The holding frame 5 of this embodiment has a larger diameter than the lens frame 2 and has a fitting recess 15 into which the lens frame 2 fits. Reference numeral 9 denotes a set screw which is screwed to the holding frame 5 so that the tip thereof presses the outer surface of the lens frame 2 to hold the lens frame 2 and the holding frame 5 in a connected state.

In this embodiment, the holding frame 5 is assembled to the lens frame 2 so that the lens frame 2 fits into the fitting recess 15. By this assembling, the first contact portion 8 of the holding frame 5 contacts the outer peripheral portion of the lens surface 1a of the device-side lens 1. Thus, similarly to the first embodiment, the distance between the device-side lens 1 and the conversion lens 4 is determined only by the distance a between the first contact portion 8 and the second contact portion 10. The thickness of the lens 4 and the accuracy of the contact portion where the lens frame 2 and the holding frame 5 contact each other have no influence on the positional relationship between the lenses 1 and 4.

In addition, according to this embodiment, the relative position of the conversion lens 4 can be fixed with high accuracy by increasing the dimensional accuracy of the holding frame 5 with respect to the device-side lens 1, whereby the conventional conversion lens can be fixed. Then, it is possible to use an impossible or meaningless advanced aberration correction and high magnification lens as a conversion lens.

Further, in this embodiment, the connection is made by fitting instead of the screw. Since the screw is also a mechanism that converts rotational motion into translational motion and decelerates it, it is difficult to control the pressure with which the holding frame 5 of the conversion lens 4 pushes the device-side lens 1 with the screw.
In the connection by fitting, since there is no deceleration mechanism, it can be attached to the device side lens 1 without causing distortion, scratches and the like.

(Third Embodiment) FIG. 3 shows a third embodiment. In this embodiment, the holding frame 5 is formed by the inner frame 11 and the outer frame 12 outside the inner frame 11. The inner frame 11 is formed with a first contact portion 8 that contacts the outer peripheral portion of the lens surface 1a of the device-side lens 1 and a second contact portion 10 that contacts the outer peripheral portion of the lens surface 4a of the conversion lens 4. I have. On the other hand, a fitting recess 16 into which the lens frame 2 fits is formed in the outer frame 12.

Further, a biasing means comprising a coil spring 13 is disposed on the holding frame 5. An end of the inner frame 11 on the opposite side to the lens frame 2 is inserted into the coil spring 13 to bias the inner frame 11 to move in the direction of the lens frame 2. A stopper 17 is provided inside the outer frame 12 to prevent the inner frame 11 from slipping out of the outer frame 12 by this urging force.
Are formed.

In this embodiment, the holding frame 5 is assembled so that the front end surface of the lens frame 2 comes into contact with the stopper portion 17 of the outer frame 12, and then the set screw 9 is tightened.

In this assembled state, the inner frame 11 is translated with respect to the outer frame 12 by the urging force of the coil spring 13,
The first contact portion 8 is pressed against the lens surface 1a of the device-side lens 1, and the positional relationship between the device-side lens 1 and the conversion lens 4 is defined. In this case, the tip surface of the lens frame 2 is accurately perpendicular to the optical axis of the device-side lens 1, and the outer diameter of the lens frame 2 is precisely concentric with the optical axis of the device-side lens 1. That is, the fitting inner diameter of the outer frame 12 with the lens frame 2 and the fitting inner diameter of the inner frame 11 are coaxial, and the stopper portion 1 of the outer frame 12 with which the lens frame 2 abuts.
The contact surface 7 is perpendicular to the inner diameter of the outer frame 12 fitted to the lens frame 2, and the outer diameter of the inner frame 11 fitted to the outer frame 12 and the optical axis of the conversion lens 4 are concentric. desirable.

In the assembled state, the gap between the device-side lens 1 and the conversion lens 4 is determined by the first contact portion 8 of the inner frame 11 contacting the lens surface 1a of the device-side lens 1 and the conversion lens 4. It is determined only by the distance a of the inner frame 11 to be in contact with the second contact portion 10, and by assuring the accuracy of this dimension, the distance between the lenses 1 and 4 can be fixed very accurately. Therefore, the thickness of the lenses 1 and 4 and the accuracy of the contact portion where the lens frame 2 and the holding frame 5 contact each other have no influence on the positional relationship between the lenses 1 and 4.

When the first contact portion 8 comes into contact with the lens surface 1a of the device-side lens 1, which is a sphere, the holding frame 5
Are automatically fixed along the center of the spherical surface of the device-side lens 1, and the conversion lens 4 is supported by the second contact portion 10.
By improving the degree of parallelism and concentricity of 10 with high accuracy, concentricity between the device side lens 1 and the conversion lens 4 can be ensured.

According to this embodiment, the device-side lens 1
By increasing the dimensional accuracy of the holding frame 5, the relative positional relationship of the conversion lens 4 can be fixed with high accuracy. As described above, since the Kosiversion lens 4 can be accurately fixed to the device-side lens 1 of the main body 7 of the optical device, it is possible to use a high-magnification correction and a high-magnification lens, which was impossible or meaningless in the past, as a comparison lens. . Further, the outer frame 5 of the conversion lens 4 can be positioned with respect to the lens frame 2 of the device-side lens 1 by fitting and the first and second abutting portions 8 and 10, and furthermore, held by the spring 13. Since the frame 5 is constantly pressed against the device-side lens 1 with a constant force, the frame 5 can be safely and easily attached without skill.

FIG. 4 shows a fourth embodiment. The device-side lens 1 of the stereomicroscope including the objective lens is held by the lens frame 2, and the lens frame 2 is fixed to the main body 7 of the stereomicroscope by a screw portion 18, and the image is stored in the main body 7 of the stereomicroscope. Are divided into left and right lens groups 21 and 22 for observation.

The conversion lens 4 is the device-side lens 1
Is performed with high accuracy, and is held by the holding frame 5 in a state of being in contact with the second contact portion 10. The holding frame 5 is formed by an inner frame 11 and an outer frame 12 as in the third embodiment, and the inner frame 11 is urged in the direction of the device-side lens 1 by a coil spring 13 as urging means. I have. The outer frame 12 and the lens frame 2 are joined by screwing, and therefore, a female screw 3 and a male screw 6 that are screwed to each other are formed at these corresponding portions.

In this embodiment, the internal thread 3 is connected to the external thread 6
Is assembled by screwing them together. By this assembling, the front end surface of the lens frame 2 and the rear end surface of the outer frame 12 abut, and the holding frame 5 is fixed. In this assembled state, the inner frame 11 is translated with respect to the outer frame 12 by the urging force of the coil spring 13, and the first contact portion 8 is pressed against the lens surface 1a of the device-side lens 1, and the device-side lens 1 is pressed. The positional relationship between 1 and the conversion lens 4 is defined. In this case, the tip surface of the lens frame 2 is accurately perpendicular to the optical axis of the device-side lens 1, and the female screw 3 of the lens frame 2 is concentric with the optical axis of the device-side lens 1 with high accuracy. The inner diameter of the fitting between the male screw 6 of the outer frame 12 and the inner frame 11 is coaxial, the contact surface between the outer frame 12 and the lens frame 2 is perpendicular to the male screw 6 of the outer frame 12, 11 outer frame 1
It is desirable that the outer diameter of the fitting with the lens 2 and the optical axis of the conversion lens 4 be concentric.

In the assembled state, the gap between the device-side lens 1 and the conversion lens 4 is determined by the first contact portion 8 of the inner frame 11 contacting the lens surface 1a of the device-side lens 1 and the conversion lens 4. It is determined only by the distance a from the contacting second contact portion 10, and by securing the dimensional accuracy between these two surfaces, the mutual distance between the lenses 1 and 4 can be accurately fixed. Therefore, the thickness of the lenses 1 and 4 and the accuracy of the contact portion where the lens frame 2 and the holding frame 5 contact each other have no influence on the positional relationship between the lenses 1 and 4.

When the first contact portion 8 comes into contact with the lens surface 1a of the device-side lens 1, which is a sphere, the holding frame 5
Are automatically fixed along the center of the spherical surface of the device-side lens 1, and the conversion lens 4 is supported by the second contact portion 10.
By improving the degree of parallelism and concentricity of 10 with high accuracy, concentricity between the device side lens 1 and the conversion lens 4 can be ensured.

According to this embodiment, the device-side lens 1
By increasing the dimensional accuracy of the holding frame 5, the relative positional relationship of the conversion lens 4 can be fixed with high accuracy. As described above, since the Kosiversion lens 4 can be accurately fixed to the device-side lens 1 of the main body 7 of the stereomicroscope, a high-aperture correction and high-magnification lens, which was impossible or meaningless in the past, can be used as a conversion lens.

Although a stereomicroscope requires an objective lens with high magnification and accurate aberration correction, it has been difficult to provide an objective lens at a price acceptable to the market with a dedicated design. This embodiment makes it possible to use the original objective lens by removing the conversion lens and use it at a new high magnification with the conversion lens at low cost, and to fix the positional relationship of the conversion lens to the best. Therefore, high performance can be provided.

Further, the outer frame 5 of the conversion lens 4
Is screwed into the lens frame 2 of the device-side lens 1
In addition, since the holding frame 5 can be constantly pressed against the device-side lens 1 with a constant force using the spring 13 without using any skill, it is safe and secure. Can be easily installed.

The present invention includes the following inventions. (1) A lens frame of an optical device holding a device-side lens, and a holding frame holding a conversion lens and detachably coupled to an end of the lens frame, wherein the holding frame and the lens frame are screwed. An attachment structure for a conversion lens, wherein the attachment structure is combined. (2) A lens frame of the optical device holding the device-side lens, and a holding frame holding the conversion lens and detachably coupled to an end of the lens frame, wherein the holding frame and the lens frame are fitted. An attachment structure for a conversion lens, wherein the attachment structure is combined. (3) In the above (1) or (2), the holding frame includes an inner frame in which the first contact portion and the second contact portion are formed, and stores the inner frame and the lens. An attachment structure for a conversion lens, comprising: an outer frame detachably connected to an end of the frame; and an urging member for urging the inner frame to move toward the lens frame.

[0044]

According to the present invention, the positional relationship and the distance between the device-side lens and the conversion lens of the optical device can be fixed with high precision, so that a high-precision, advanced aberration correction and high-magnification conversion lens can be mounted. Can be.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of Embodiment 1 of the present invention.

FIG. 2 is a cross-sectional view of Embodiment 2 of the present invention.

FIG. 3 is a sectional view of a third embodiment of the present invention.

FIG. 4 is a sectional view of a fourth embodiment of the present invention.

FIG. 5 is a sectional view of a conventional conversion lens mounting structure.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Device side lens 2 Lens frame 4 Conversion lens 5 Holding frame 8 1st contact part 10 2nd contact part

────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] November 11, 1996

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0003

[Correction method] Change

[Correction contents]

Such a conversion lens is in the compact camera is mounted by covering the camera body, in other optical instruments Utility Model 60-163
As described in Japanese Patent No. 422,422 and US Pat. No. 3,459,991, while forming a screw on the front end of a lens frame on the device side, forming a screw on a holding frame for holding a conversion lens, and screwing these screws together. , Its being made.

[Procedure amendment 2]

[Document name to be amended] Drawing

[Correction target item name] Fig. 1

[Correction method] Change

[Correction contents]

FIG.

[Procedure amendment 3]

[Document name to be amended] Drawing

[Correction target item name] Figure 2

[Correction method] Change

[Correction contents]

FIG. 2

[Procedure amendment 4]

[Document name to be amended] Drawing

[Correction target item name] Figure 3

[Correction method] Change

[Correction contents]

FIG. 3

Claims (2)

[Claims] An end of a holding frame for holding a conversion lens is brought into contact with an outer peripheral portion of a lens surface of a device-side lens of an optical device, thereby positioning the conversion lens with respect to the device-side lens via the holding frame. A method for mounting a conversion lens. 2. A lens frame of an optical device holding a device-side lens, and a holding frame holding a conversion lens and detachably coupled to an end of the lens frame, wherein the holding frame includes the lens. A first contact portion formed to project from an end on the frame side and contacting an outer peripheral portion of a lens surface of the device-side lens when the holding frame is mounted on the lens frame;
And a second contact portion which is formed so as to face the contact portion, and which fixes the conversion lens by contacting the outer peripheral portion of the lens surface of the conversion lens. Mounting structure.